Data rates continue to increase in digital systems, communication systems, computer systems, and in other applications. In such applications, various devices communicate data using signals that may be encoded with information in the form of signal levels (e.g., amplitude) in certain intervals of time. Proper decoding of signals, for example, may involve measuring small signal levels in the correct time intervals. As data rates increase, margins of error for the signal level timing tend to decrease.
Likewise, operating frequencies for some analog signal processing systems continue to increase along with advances in telecommunication technologies, for example.
In general, some signals may propagate along a signal path from a transmitter to a receiver. For example, a signal may propagate through a transmission line, such as a coaxial cable, printed circuit trace, or twisted pair, for example. In some applications, transmission lines may provide a relatively constant characteristic impedance. Similarly, signal paths in the source and the receiver may have impedances that differ from the transmission line impedance.
For high frequency signals, impedance discontinuities may result in signal reflections. In some cases, signal reflections can result in significant signal loss and/or distortion.